COMMENTS: First prototype flew in April 1944, but was sunk early 1945 by strafing Mustangs. At the end of WWII the second prototype was virtually complete and construction of the third was in an advanced stage

COMMENT: The Blohm & Voss Ha 139 was an all-metal inverted gull wing floatplane. With its four engines it was at the time one of the largest float-equipped seaplanes that had been built. The inboard engines were mounted at the joint between the inboard anhedral and outboard dihedral wing sections, above the pylon-mounted floats.
The aircraft were flown by Deutsche Luft Hansa (DHL) on transatlantic routes between 1937 and 1939. Catapult-launched from an aircraft tender they were able to transport 500 kg of mail over a distance of up to 5,000 km.
On the outbreak of WW II, the planes were transferred to the Luftwaffe and used for transport, reconnaissance and minesweeping work over the Baltic Sea. They were not particularly suited for military use. After service with DLH, the Ha 139B was modified as the Ha 139B/Umbau (Reconstruction) with an extended glazed nose accommodating a navigator and a spherical Ikaria mount for a machine-gun. Further machine guns were mounted in the cockpit roof hatch and in lateral mountings on either side of the rear fuselage. The Ha 139B/Umbau was later modified into a mine sweeping (Minensuch) aircraft Ha 139B/MS fitted with a large magnetic sensing loop strung between the nose, floats, wing-tips, and tail unit.
Further development of the Ha 139 led to the land based version Blohm & Voss Bv 142 which had its first flight in October 1938 (Ref.: 24).

COMMENT: The Blohm & Voss BV 142 was a civil aircraft developed for the transatlantic airmail service, originally designed for the Deutsche Luft Hansa (DHL). The first prototype was flown on 11 October 1938. The aircraft had four engines mounted on a low inverted gull monoplane wing, high horizontal stabilizer, and a double vertical tail, based on the Blohm & Voss Ha 139 float plane.The wing center section was strengthened by a typical Blohm & Voss cross-girder, which consisted of a large-diameter pipe. This transverse tube (divided internally into five sections) also acted as a fuel tank. The center wing was metal-covered, while the outer wings were fabric-covered. The fuselage was of metal and had an approximately circular cross-section. Each main landing gear leg had dual wheels and was fully retractable, as was the tailwheel. The landing gear was hydraulically lowered and retracted.
Only four prototypes (V1 through V4) were built. These aircraft were tested by Lufthansa and used briefly in the postal service. However, the outbreak of WW II ended further development of the civilian project. Soon after, it was proposed to convert all four prototype BV 142’s to long-range maritime patrol aircraft. The BV 142 V2 thus underwent a trial modification. It was fitted with an extended nose section with extensive glazing (like the Heinkel He 111H-6), defensive armament (MG 15 machine gun in the nose, twin-beam positions, a ventral cupola, and a powered dorsal turret), a compartment for ordnance in the fuselage, and navigation and military radio equipment. The BV 142 V2 was redesignated BV 142 V2/U1 while the V1 was similarly converted. Both were used operationally from late 1940 and were posted to the Luftwaffe’s Second Surveillance Group. However, their performance was disappointing, and after only a few missions, they were withdrawn from service in 1942. The two other aircraft (V3 and V4) were used as transport aircraft and could transport 30 fully equipped soldiers over 4,000 km. The ultimate fate of V3 and V4 is unknown. It was later planned to use the V1 and V2 to carry the Henschel GT 1200C guided torpedo, but the plan was scrapped (Ref: 24).